To texture makers from a builder, regarding alpha

Hi folks. I just want to put in my two cents. I am by no means a texture artist, I am simply a builder and a user of textures. However, as such, I occasionally encounter textures made by texture artists who quite apparently are not builders.

What I am referring to here, is the use of alpha. I recently bought some textures, for instance, that were advertised as being 512x512. But, many of the textures had a tiny object in the center of a sea of alpha. In order to get the object to fill the prim, the repeats had to be set to about .200x.200. Needless to say, the actual texture was not at a resolution of 512x512. If you, as a texture maker, MUST use alpha, please make sure that the object it is surrounding fills, or at least very nearly fills, the frame.

That isn't the biggest problem to do with alpha, however. The next one is the big one:The use of alpha when it is not necessary. I see it all the time. Otherwise opaque textures that are surrounded by an alpha layer for no apparent reason, other than habit, I guess.

Take, for instance, a round object in a texture, like a medallion. Say I wanted to put that medallion on the end of a cylinder. So I adjust the texture so the round medallion exactly fits the cylinder end, with none of the alpha "showing." Even so, when someone walks by my cylinder in a prim skirt which also has alpha, chances are that skirt or a portion thereof will disappear while it is next to the cylinder. It would be much better in this case if that alpha layer were to be replaced with almost any color of an opaque layer. This way it would not interfere with prim skirts and the like.

Now, I know, many of you would be reluctant to sell such things without a surrounding alpha layer, just because that is what people are used to seeing, and that is what they expect. So, how about putting two copies of each texture in the pack, one with alpha for the people who don't know any better, and one without, for builders who do?

Of course there are shapes that will require that alpha surround, because they have protrusions at their edges that must have alpha between them. I am not talking about those, here. What I am talking about are textures that will fit perfectly on a prim face, perhaps with a little adjustment, and when they are properly adjusted, no alpha would be "showing" anyway.

If you have not encountered this problem with alpha, or have not noticed it, please let me assure you, it exists. If you like, IM me inworld and I can send you some example prims so you can see what I'm talking about.

your annoyance is valid, but the best solution is to make your own.

You can always just save the texture, insert an opaque layer with a colour of your choice underneath, save it as 24-bit TGA and reupload.

At least get people to think about this.

I don't know how often I walk by a rock or wall or something else that has no obvious alpha channel, and see my alpha hair or alpha prim clothes flicker.

I've had to rip and re-upload textures in several products I've bought to get rid of the alpha channel.

I think a lot of texture creators and builders are just too used to the bad old days when the only supported formats were TGA and BMP and just upload everything in TGA by habit.

[it would also be nice if the Labs did something about the alpha layering problem... there must be something they can do, because it WAS less of a problem before Windlight]

Some good points there. As a texture artist who also IS a Builder, I agree.

Haven't encountered the first issue the OP mentions, of a tiny object in a large field of alpha. Most texture artists that are selling something like a figure for a charm bracelet or other graphics that need alpha around the outside will crop the image as tight to the non-alpha parts as they can, to get in as much detail as they can for what is visible.

For trees and such, where there will be an "exposed" alpha edge that people can see above the foliage, it IS a good idea to have an alpha edge of about two pixels width all the way around the image, so the base of the trunk doesn't tile as an asterisk in the sky above your three-prim tree. But 2 pixels is quite sufficient for that.

Agree 100% on using a solid fill beyond what should be a texture for something round. Where I encountered that the most was on "throw rug" patterns that were intended for making a round or oval rug. Clearly the maker was thinking of just throwing the texture on a flat box prim, and never considered that placing them on the end of a cylinder and using a solid fill beyond the used limits works better. I've done as one of the other responders suggested myself, and taken textures made by others and added a solid fill past the edges, so I could have a non-alpha rug texture to use on the end of a cylinder.

I'll add a couple of other considerations...

If you're selling wall textures with an alpha window in them, also sell the same texture with the window shaded black, and as a non-alpha. Why? Because then a Builder who wants to do a higher-prim version of that window can use portions of that texture on individual prims, with NO alpha needed, and use the alpha'ed portion only for the window prim. For example, I might do full-prim construction on the ground floor, to avoid alpha conflicts with the shrubbery around the foundation, but might want to use the one-prim alpha version of that wall for the upper floors, where the alpha conflict is less of an issue.

(Yes, if a builder purchased the alpha version and wants the same thing with black fill and no alpha, they can do the download, add fill and upload dance, but they shouldn't have to bother...)

Also, if you sell wall textures with a window in them, PLEASE make suitable matching interior textures to go with the exterior version! What good is it to have a lovely cottage window surrounded by cedar shingles and ivy vines, if the Builder can't match that on the inside with something that looks like it belongs inside the house?

And any wall and window sets with alpha windows in a wall texture should always offer the same wall with no window at all, as a 24-bit texture (no alpha).

And if everyone did that, there would be no market for textures.

Yes, but when I buy a texture, I don't want to have to edit it to make it useful.

Well, we certainly seem to agree, thanks for adding a couple of things I forgot. Speaking of wall textures with windows, if the builder happens to texture every face of a wall prim with a texture with alpha windows, once it is placed next to an adjoining wall prim, from different angles the prims will seem to have anything from slight gaps to 1/2 meter gaps between them. This, of course, is nothing texture makers can fix. I just want them to be aware of the potential perils of alpha.

Yes, and I double-agree regarding appropriately matching interior textures. In the old days I had to settle for windows with rounded tops on builds with rectangular exterior winndows quite frequently. Fortunately, this is not the sort of thing most people notice. And yes, an interior texture with a window, and with no matching solid texture without window is virtually useless. Yet I see it all the time. I won't buy sets like that.


Please understand, folks. Right now, I want to build and script. I don't WANT to make my own textures, or edit other people's. There may come a day when I want to learn to make all my own textures, but for now I enjoy going texture shopping, and even occasionally get inspiration for builds from a new texture set.

Plus, I have plenty of clothes, and I need SOMETHING to spend L$ on.

I have done solid textures with png and it still acts like a transparent and I still have
the glitch.
The only way to totally avoid the glitch if this is the issue is for windows
do a mirror effect with gradient type of surface preferably black and white
and upload it as nontransparent tga.
The problem with that is then you're closed in the house with no way to look
out and depending on size of build there thing that happens to camera at
least for me that makes me claustrophobic.
I often wished I knew how to script because I would make a house that walls
were touchable that you could change the textures to suit whatever purposes.
I never seen houses like this.
If you need help I would be willing to help with whatever to understand what you're talking about, because I don't entirely understand it.
I do textures and creative stuff for fun most of time. It is fun to do building things
with others too.
Most of stuff I make rarely sells there is always someone else out there who is better
known and my things are usually missed.
I could always use some upload money personally
I don't know about anyone else but for me making textures most of time is just what do
for fun and money part is nice but it's not really required as long as I have
enough to do what I want to do.
The thing is I don't do CGI textures, they are hand drawn and sometimes I use
small bits of photo sourced images but I don't like photo sourced.
Problem with photo sourced is hard to map the right locations of space for the
prim surface for me, and often when I have seen others use it the textures look
very squished or blurry when its all based on photos.
I am learning how to use the prim surfaces with grids to paint specific things
for specific spaces but I still got ways to go.
I build but I am really into building but I am willing to understand what you're talking about for educational purposes and conduct some experiments.
Somethings though because I am not really into building I don't really get the
repeats as someone who builds all the time.
Problem I have had with doing matching interior and exterior windows is I just get
distracted and go on to something else often and then forget hey these windows need
a exterior or interior surface.
I have numerous hand painted curtains and few mini-blinds experiments that I never uploaded but I keep meaning to create interior and exterior windows but I keep getting distracted.
I thought about interior and exterior windows with no alpha with curtains, mini blinds but
layers I just never got around to it.

if your a builder

genetica 2.5

and a graphics editor

feel free to ask questions, but if you learn a texture generator, and a photo editor to even a low novice level, you will get EXACTLY what you want, and the ability to make complex map, with next to no effort

and since your a commercial builder the cost of software will be quickly regained

I'm not a builder but I've used some textures of my own on buildings.
Since you are builders... Isn't this a transparency problem? Doesn't png's have the same issues?

Png is a just easier way to make transparent textures and it works just like if it was transparent regardless if its design is total solid textured fabric, wall stainglass, or semi-transparent made window, tree or flower texture.
I stumbled upon this when I made some hand drawn damask fabric and made mistake of not saving it as tga but as png and put it on sofa I had built. It behaved in same way any
transparent would with the gl glitch except the png texture was solid.

Depends on the program you use. It's possible to have 24 bit PNGs, and if SL treats 24-bit PNGs as if they're 32-bit PNGs that's a bug. If your program saves a 24-bit image as a 32-bit PNG, that's a bug too.

It's also possible to have 32-bit BMPs, as I found when I accidentally made one in GIMP.

REALLY? Interesting... Good to know! Thanks!

in photoshop at least, if you save your png using "save for web and devises" instead of the usual save as, it gives an option to remove the alpha channel from it, otherwise, even if it has none, an alpha channel will be included in the file.

personally, I have found I prefer to just save as a 24bit tga when I want to make sure there is no alpha, or it's not meant to be alphaed in any way

In the Gimp, you check 'save background colour' to make a 24-bit, and leave it unchecked for a 32/alpha.

SL recognises the Gimp-uploaded 24-bit pngs, so I presume it recognises the same from Photoshop or wherever else.

just one minor additon, used to see it alot, not so much anymore (at least with newer textures)

TGA: as a format there is nothing wrong with it, in fact, it's superior to png IMHO (this discussion has been hashed numerous times) however some programs (and/or people that din't know better) would save solid textures as 32bit (which includes an alpha channel) as opposed to 24bit (which does not) even when there was no reason to do so...

thankfully most products now save tga to the correct bit depth based on the presence/absence of an alpha channel. but if you'r using an older product, or are insanely curious as to what differnt override settings do, 24bit for solids, 32bit for alpha.

I really hard time with tga alphas I tried and tried for months even had
friend show me how with very simple pattern but with more complex I
got all confused.
I also use older Photoshop I found it easier to do PNG save as then alpha tgas
The only issue I found with it is you must use web safe colors.
It works for me I don't see the quality difference personally in quality.

My problem with TGA is that it's not strictly an image format, it's a way of encapsulating images... that can be in multiple formats... in a single wrapper, and quite possible to create a TGA in one program that can't be read in another.

It's definitely a much more versatile format, but i've been burned by incompatible TGAs too often over the years to really trust it.

That's one reason when we were designing PNG we didn't just make it a new encoding in an existing format like IFF (though we did base it on an IFF derivative).

Edit: there is no shortcoming in PNG alpha that TGA is needed to fix. There have been programs that did a poor job of writing PNG with alpha in the past, but there's no difference in the actual decompressed bitmaps between a properly created 32-bit PNG and TGA.